A Numerical Approach for Determining Double-K Parameters for Concrete Component

The determination of double-K parameters of concrete components is typically carried out through experimental and analytical methods within the framework of Linear Elastic Fracture Mechanics (LEFM). Testing large-scale concrete components with arbitrary geometry presents significant challenges. These challenges also affect the evaluation of double-K fracture parameters. To address this problem, this paper proposes an alternative numerical approach. The method consists of two main steps and is designed to determine the double-K parameters for large-scale concrete components. Based on known physical properties obtained through material property testing, the numerical results demonstrate good agreement with both analytical solutions and experimental data. In this approach, a solution-based crack propagation path is obtained using an XFEM-cohesive zone model (CZM) analysis. The critical crack opening displacement [Formula: see text] is employed to discretize the physical crack from the fracture process zone, while simultaneously filtering out the nodes participating in crack face regeneration. The resulting physical crack model is then reinserted into the original model to perform a static XFEM crack analysis, yielding the fracture toughness curve and double-K parameters. Fracture energy and specimen thickness are identified as factors influencing [Formula: see text]. Three-Point-Bending (TPB), Compact-Tension (CT), and semi-circular bending (SCB) specimens are employed to validate the accuracy of the proposed approach and investigate the characteristics of [Formula: see text]. A tension-shear benchmark test specimen is employed to demonstrate the robustness and functionality of the originally developed crack regeneration technique. The proposed method offers an effective approach to determine the double-K parameters and evaluate the stress intensity factors (SIFs) of arbitrarily shaped cracks. All source code is available upon request by contacting the corresponding author.